In science fiction and stuff, aliens are usually depicted as scientific superbrains with no religion.

But what if aliens landed on a campaign world and brought their gods with them?

Wouldn't that be crazy?

MoonHunter:
The only story/ story arc was the DC comics Invasion Story arc. For about a year after the end of it, the heroes were randomly encountering alien related supernatural events. Swamp Thing addressed this in an issue (sorry can't find the number).

The big thing is that the afterlife or spiritual world is defined by the beliefs of those who go there. So each species has its own piece of spiritual real estate. That "real estate" would be divided up to heavens/ hells/ or appropriate ellysium fields. If you believed in "your worlds" religion, your view of the afterlife would match your religion's mythology. If you are the only dead alien of your type, you are actually in control of your "heaven/ hell". If there are many of you, the world is a composite of everyone's belief.

The various gods, they can only function in their people's spiritual realms. Outside of those realms, they have little to no power.

Of course there is the Torg view of this. If enough of your people are in a place, defining the reality there, then your god has power there.

CaptainPenguin:
Well, I tend to disagree on the whole "Gods function only in the world of the same belief" thing.

I think that if the Alien Gods brought along enough of the Aliens with them, then they would be just fine, because, after all, Aliens on another planet still have the same beliefs, (I mean, at first. After a few centuries, they might be influenced by native beliefs.) so they still have the same religious philosophy as on their homeworld.

MoonHunter:
"Gods function only in the world of the same belief" thing. If that was not the case, then those Gods would already be here on the world. Why aren't they influencing things?

If every world has access to every god, even those from alien places, why aren't alien gods making their own cultists, clerics, and paladins and creating a beach head of indigionous worshipers?

So since those gods are already here, then there would be no difference when the aliens arrive.

Ria Hawk:
Maybe gods can only exist where their worshippers are. Therefore, they exist in the alien world. When the aliens come, the gods can manifest where they are.